The present invention relates generally to universal joints, and more particularly to a bearing system in a universal joint for journaling the bearing pins of a cross trunnion in such a joint.
The present invention is applied in a universal joint of the type having a pair of journals with seating bores having roller bearings for journaling a bearing pin of a cross trunnion which is received in the bore. In this type of universal joint, the journals are mounted on a shaft flange and means, such as projections, are typically provided on the journal to engage radial grooves on frontal end faces of the flange to prevent radial and lateral displacement of the journal.
Bearing systems of the foregoing type, such as shown in German Patent No. 624,185, have the disadvantage that once the cross trunnion is positioned in the universal joint and assembled with the journals for supporting the oppositely extending pairs of bearing pins of the trunnion, it is no longer possible to adjust the axial clearances between an end face of each trunnion pin and the bottom wall of its respective seating bore in the journal. Since the journal in this type of universal joint is prevented from both radial displacement and lateral displacement by the use of the projections from the journal engaging a groove in the flange, the amount of clearance between the end face of the pin and the bottom of the seating bore will be solely a function of the manufacturing tolerances of each of the elements. Accordingly, it is virtually impossible to adjust or in any way affect concentric alignment of the parts. Additionally, the lack of precise clearance settings frequently result in increased friction between the journal surfaces and the end face of the trunnion pin which will inevitably lead to the formation of deep scoring or grooving in either the journal or the pin, or will result in cold-welding together of the parts. Also, large clearances resulting from poor manufacturing tolerances, which cannot thereafter be adjusted, may result in imbalances causing axial forces produced by the effects of centrifugal forces.
It is accordingly the principal object of the present invention to provide a bearing system for use in a universal joint which permits adjustment of the clearances between the parts while still preserving the essential simplicity of the bearing assembly.
Another object of the present invention is to provide a simple and relatively inexpensive means for removal and replacement of worn parts in the joint.
Other objects, features and advantages of the present invention will become more apparent from the detailed description of the invention in connection with the accompanying drawings to be described more fully hereinafter.